The present invention relates to underground distribution systems and more particularly concerns valve boxes for use with underground water, gas, electric, telephone and sewer lines.
Modern underground distribution systems employ valves, boxes and lines made of plastic to avoid the effects of corrosion which plague older metal systems. However, innovative improvements often result in new problems. Lightweight plastics are not able to withstand some of the external forces that their earlier metal counterparts were able to absorb. Furthermore, the structural variations made possible by the use of plastics have resulted in a wide range of exterior valve dimensions.
Consequently, valve boxes designed to suit one particular valve can significantly compromise the structural interrelationship of the valve, the box and the lines when used with a different valve so as to create weak points in the system which will eventually result in system failure. On the other hand, in terms of both space and economics, it is highly undesirable to have to stock as wide a range of boxes as valves. Clearly, then, there is a need for a universal valve box which minimally compromises the structural strengths of the valve, box and line assembly. No such universal valve box is presently available.
It is, therefore, an object of the invention to provide a valve box which will work effectively with a variety of valve structures. Similarly, it is an object of the invention to provide a valve box structurally coordinated with a variety of valves and lines so as to effectively distribute the forces exerted upon these underground distribution members. Another object of this invention is to provide a valve box which is easy to install and easy to access after installation. A further object of this invention is to provide a valve box that prevents rotation of the valve within the box after installation.